On very general grounds we can state that the determination of the primary mass composition cannot be obtained in a model-independent way, the description of hadronic multi-particle production at the highest energies depends on the extrapolation of the accelerator data on cross sections up to center of mass energies \(\sqrt{s}\simeq 400\)  TeV. Moreover, the QCD predictions for the bulk of hadronic production at these energies are considerably affected by the hadronic interactions model assumed (see [1]}, [2]} and references therein).
